Battery Load Tester

maxwell11 wrote:

I do try to buy USA made items when I can, even if they cost a bit more, might save some old boy or girls job.

Well said and probably goes towards the 2016 Top Statement of the Year Award. :B

maxwell11 wrote:
The motor on my 2005 Dodge diesel was not kicking over as fast as it had been the last few days.

got back from Christmas vacation and it would not start,

I disconnected each positive lead from the batteries and charged up each battery.
next day took it down to the auto parts store to get the batteries check as they were installed on October 2011.

Sales clerk disconnected one positive clamp, then using a Battery Load Tester checked both batteries, both batteries test bad under load.

so I bought new batteries. but got $60 rebate on the old ones.

however, after I got home I got to thinking,

even thought he showed me they failed on his "battery load test machine"

I really did not understand why they were still starting my truck after the battery recharge I gave them the night before, if they wre bad.

also, if one battery had gone bad, what was the likely hood, both batteries were bad???????????

however, if one was bad I was going to change both out for new batteries.

I am now thinking about buying me one of those Battery load test machines.

anyone else have one and use it,

was I taken in on the old bad battery load test trick, maybe I should have had him test these new batteries I bought on his machine, before I left the premises ??????

ah well, the old truck starts fine now with plenty of zip,

To me you did the only correct thing to do. You bought 2 new batteries.

chevman

OP has not said what temperature he was in. Diesels don't turn over very good when cold. They need at times to have block heater on.

Batteries start to go bad the minute they come off of the assemble line.

It's not like they are great, great, great, great, bad.

It's more like they are great, great, good, good, ok, ok, bad.

In other words, much like people, they slowly wear down and wear out over a lifetime. :B

I take old batteries out of my diesels that won't pass load test and put them in my equipment that I run once a year. I can get several more years out of my batteries doing this. :)

If you want to buy a load tester I suggest you buy a newer type electronic model rather than the old carbon bank types. Last time I checked one could get a nice new electronic model for about 75 to a 100 bucks.

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I had some trouble with mine, but I think it was just corrosion. I left them sit for about 3 weeks without a trickle charger which I usually don't do and they wouldn't even crank to start in 35F weather.

Earlier in the year, I think I sprayed some anti-corrosion on them as an after-thought because they looked so good yet and I was in a hurry after working on some other batteries. Then I promptly forgot about them since they looked done. Then I ended up working in the cold.

With headlights on, one terminal dropped 4+ volts across the post-to-clamp. I thought it a little odd that the truck did not start with the other battery but the system was probably severely undercharging if the alt voltage fooled it as high when it wasn't getting into the batteries. A good cleaning and charge and they seem fine now. I won't really know till spring, or even next fall, as I seldom start it in winter unless the Excursion V-10 is out of service.

I normally trickle charge the batteries constantly when they aren't used. The OEM battery in my previous Ranger sized pick-up lasted about 15 years this way. The idea is to never let the batteries drain down at all and prevent sulphation. When peaked out by a trickle charger, such batteries also seem to crank in winter like in summer. The most common one I used was a $5 sale Harbor Freight unit that was voltage limited, but I also have a couple of $20 Sears sale Schumachers now.

A good source of info is The 12volt Side of Life (Part 1). Don't miss Part 2.
The chart below is taken from the site:

Using any reasonably accurate digital voltmeter, one can check the percent of charge of RV batteries or, in this case the voltage of the diesel system after the headlights have been on a bit. Good batteries maintain decent voltage longer and a good time to benchmark thee standard battery is now since they are new. Fold the info into your vehicle owners manual. Some years down the road, when you have reason to doubt the batteries integrity, the measurements can be checked against the new battery measurements. Even cranking voltage can be measured so not only the sound, but exact loss can be determined.

Harbor Freight has a small cheap meter, that works and they often sell it for $5, or are even free. I bought one for $3 and gave it to my buddy after I calibrated it against a good Fluke meter. I fine tuned the HF meter on the inside pot to read exact against the Fluke standard, but it was only .1 vdc different, pretty close to start. Then just use the chart above to monitor your RV or parked truck. Best to leave a trickle charger on all the time. I believe batteries sulphate faster in summer.

Wes
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